This disclosure relates to a seat system for a vehicle. In an X, Y, Z coordinate system, a person can be subject to motion in six degrees of freedom. These degrees of freedom include rotation about the X, Y and Z axes, and translation substantially parallel to each of these axes. When traveling in a vehicle such as a farm tractor or a car, a person can be quite sensitive to vehicle rotations about roll and pitch axes. As such, passengers in vehicles with relatively stiff suspensions (e.g. farm tractors, sports cars) can be made uncomfortable when the vehicle starts rocking side-to-side and/or pitching back and forth due to an uneven surface over which the vehicle is traveling.
U.S. Pat. No. 5,857,535 discloses a low aspect self-propelled vehicle (1) operated by a driver (4) sitting on top of it, has its seat (7) supported from beneath by a flange (12) which is pivoted to tilt about a horizontal axis (15) in the mid-vertical plane of the vehicle. The spacing between the axis (15) and the seat (7) is sufficient to ensure that when the seat is tilted about the axis by operation of a tilt control mechanism (21), the center of seat also displaces a significant extent in the uphill direction of the slope. This reduces the downhill movement of the center-of-gravity (10) of the combination of vehicle plus driver, so that the risk of the vehicle toppling is reduced.